Re: [PATCH v4 6/8] perf/tools: Enhance JSON/metric infrastructure to handle "?"

kajoljain
2020-03-12T06:16:10Z

On 3/11/20 12:04 AM, Arnaldo Carvalho de Melo wrote:
> Em Mon, Mar 09, 2020 at 11:55:50AM +0530, Kajol Jain escreveu:
>> Patch enhances current metric infrastructure to handle "?" in the metric
>> expression. The "?" can be use for parameters whose value not known while
>> creating metric events and which can be replace later at runtime to
>> the proper value. It also add flexibility to create multiple events out
>> of single metric event added in json file.
>>
>> Patch adds function 'arch_get_runtimeparam' which is a arch specific
>> function, returns the count of metric events need to be created.
>> By default it return 1.
>>
>> One loop is added in function 'metricgroup__add_metric', which create
>> multiple events at run time depend on return value of
>> 'arch_get_runtimeparam' and merge that event in 'group_list'.
>>
>> This infrastructure needed for hv_24x7 socket/chip level events.
>> "hv_24x7" chip level events needs specific chip-id to which the
>> data is requested. Function 'arch_get_runtimeparam' implemented
>> in header.c which extract number of sockets from sysfs file
>> "sockets" under "/sys/devices/hv_24x7/interface/".
>>
>> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
>> ---
>> tools/perf/arch/powerpc/util/header.c | 22 +++++
>> tools/perf/util/expr.h | 1 +
>> tools/perf/util/expr.l | 19 +++-
>> tools/perf/util/metricgroup.c | 124 ++++++++++++++++++++------
>> tools/perf/util/metricgroup.h | 1 +
>> tools/perf/util/stat-shadow.c | 8 ++
>> 6 files changed, 148 insertions(+), 27 deletions(-)
>>
>> diff --git a/tools/perf/arch/powerpc/util/header.c b/tools/perf/arch/powerpc/util/header.c
>> index 3b4cdfc5efd6..036f6b2ce202 100644
>> --- a/tools/perf/arch/powerpc/util/header.c
>> +++ b/tools/perf/arch/powerpc/util/header.c
>> @@ -7,6 +7,11 @@
>> #include <string.h>
>> #include <linux/stringify.h>
>> #include "header.h"
>> +#include "metricgroup.h"
>> +#include "evlist.h"
>> +#include <dirent.h>
>> +#include "pmu.h"
>> +#include <api/fs/fs.h>
>>
>> #define mfspr(rn) ({unsigned long rval; \
>> asm volatile("mfspr %0," __stringify(rn) \
>> @@ -16,6 +21,8 @@
>> #define PVR_VER(pvr) (((pvr) >> 16) & 0xFFFF) /* Version field */
>> #define PVR_REV(pvr) (((pvr) >> 0) & 0xFFFF) /* Revison field */
>>
>> +#define SOCKETS_INFO_FILE_PATH "/devices/hv_24x7/interface/"
>> +
>> int
>> get_cpuid(char *buffer, size_t sz)
>> {
>> @@ -44,3 +51,18 @@ get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
>>
>> return bufp;
>> }
>> +
>> +int arch_get_runtimeparam(void)
>> +{
>> + int count;
>> + char path[PATH_MAX];
>> + char filename[] = "sockets";
>> +
>> + snprintf(path, PATH_MAX,
>> + SOCKETS_INFO_FILE_PATH "%s", filename);
>> +
>> + if (sysfs__read_ull(path, (unsigned long long *)&count) < 0)
>> + return 1;
>> + else
>> + return count;
>
> Why this cast dance? We have sysfs__read_int(path, &count).
>
> Also this is more compact:
>
> return sysfs__read_int(path, &count) < 0 ? 1 : count;

Hi Arnaldo,
Yes it will be better to use like that.
>
>> +}
>> diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
>> index 9377538f4097..d17664e628db 100644
>> --- a/tools/perf/util/expr.h
>> +++ b/tools/perf/util/expr.h
>> @@ -15,6 +15,7 @@ struct parse_ctx {
>> struct parse_id ids[MAX_PARSE_ID];
>> };
>>
>> +int expr__runtimeparam;
>> void expr__ctx_init(struct parse_ctx *ctx);
>> void expr__add_id(struct parse_ctx *ctx, const char *id, double val);
>> int expr__parse(double *final_val, struct parse_ctx *ctx, const char *expr);
>> diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
>> index 1928f2a3dddc..ec4b00671f67 100644
>> --- a/tools/perf/util/expr.l
>> +++ b/tools/perf/util/expr.l
>> @@ -45,6 +45,21 @@ static char *normalize(char *str)
>> *dst++ = '/';
>> else if (*str == '\\')
>> *dst++ = *++str;
>> + else if (*str == '?') {
>> +
>> + int size = snprintf(NULL, 0, "%d", expr__runtimeparam);
>
> TIL that C99 allows for a NULL str to format and return the number of
> bytes it would write if the string was large enough... wonders never
> cease :-)
>
>> + char * paramval = (char *)malloc(size);
>
> No need for the cast, malloc returns void *, or has that changed? 8-)
> and please no space before the variable name.
>

Okk, Will take care of that.

> Humm this is all complicated, why not use asprintf and have something
> like:
>
>> + int i = 0;
>> +
>> + if(!paramval)
>> + *dst++ = '0';
>> + else {
>> + sprintf(paramval, "%d", expr__runtimeparam);
>> + while(i < size)
>> + *dst++ = paramval[i++];
>> + free(paramval);
>> + }
>
> char *paramval;
> int size = asprintf(&paramval, "%d", expr__runtimeparam);
>
> if (size < 0)
> *dst++ = '0';
> else {
> while (i < size)
> *dst++ = paramval[i++];
> free(paramval);
> }
>
>
>> + }
>> else
>> *dst++ = *str;
>> str++;
>> @@ -72,8 +87,8 @@ number [0-9]+
>>
>> sch [-,=]
>> spec \\{sch}
>> -sym [0-9a-zA-Z_\.:@]+
>> -symbol {spec}*{sym}*{spec}*{sym}*
>> +sym [0-9a-zA-Z_\.:@?]+
>> +symbol {spec}*{sym}*{spec}*{sym}*{spec}*{sym}
>>
>> %%
>> {
>> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
>> index c3a8c701609a..11eeeb929b91 100644
>> --- a/tools/perf/util/metricgroup.c
>> +++ b/tools/perf/util/metricgroup.c
>> @@ -474,6 +474,98 @@ static bool metricgroup__has_constraint(struct pmu_event *pe)
>> return false;
>> }
>>
>> +int __weak arch_get_runtimeparam(void)
>> +{
>> + return 1;
>> +}
>> +
>> +static int metricgroup__add_metric_runtime_param(struct strbuf *events,
>> + struct list_head *group_list, struct pmu_event *pe)
>> +{
>> + int i, count;
>> + int ret = -EINVAL;
>> +
>> + count = arch_get_runtimeparam();
>> +
>> + /* This loop is added to create multiple
>> + * events depend on count value and add
>> + * those events to group_list.
>> + */
>> +
>> + for (i = 0; i < count; i++) {
>> + const char **ids;
>> + int idnum;
>> + struct egroup *eg;
>> + char value[PATH_MAX];
>> +
>> + expr__runtimeparam = i;
>> +
>> + if (expr__find_other(pe->metric_expr,
>> + NULL, &ids, &idnum) < 0)
>> + return ret;
>> +
>> + if (events->len > 0)
>> + strbuf_addf(events, ",");
>> +
>> + if (metricgroup__has_constraint(pe))
>> + metricgroup__add_metric_non_group(events, ids, idnum);
>> + else
>> + metricgroup__add_metric_weak_group(events, ids, idnum);
>> +
>> + eg = malloc(sizeof(struct egroup));
>
> Shorter form that works even if you change that type:
>
> + eg = malloc(sizeof(*eg));
>
>> + if (!eg) {
>> + ret = -ENOMEM;
>> + return ret;
>> + }
>> + sprintf(value, "%s%c%d", pe->metric_name, '_', i);
>> + eg->ids = ids;
>> + eg->idnum = idnum;
>> + eg->metric_name = strdup(value);
>
> Please check strdup() return just like you checked the malloc(sizeof(struct egroup)).

Right, I missed that part, will update it.

>
>> + eg->metric_expr = pe->metric_expr;
>> + eg->metric_unit = pe->unit;
>> + list_add_tail(&eg->nd, group_list);
>> + ret = 0;
>> +
>> + if (ret != 0)
>> + break;
>> + }
>> + return ret;
>> +}
>> +static int metricgroup__add_metric_param(struct strbuf *events,
>> + struct list_head *group_list, struct pmu_event *pe)
>> +{
>> +
>> + const char **ids;
>> + int idnum;
>> + struct egroup *eg;
>> + int ret = -EINVAL;
>> +
>> + if (expr__find_other(pe->metric_expr,
>> + NULL, &ids, &idnum) < 0)
>
> Why break the above in two lines?
>
>> + return ret;
>> + if (events->len > 0)
>> + strbuf_addf(events, ",");
>> +
>> + if (metricgroup__has_constraint(pe))
>> + metricgroup__add_metric_non_group(events, ids, idnum);
>> + else
>> + metricgroup__add_metric_weak_group(events, ids, idnum);
>> +
>> + eg = malloc(sizeof(struct egroup));
>
> Ditto
>
>> + if (!eg)
>> + ret = -ENOMEM;
>> +
>> + eg->ids = ids;
>> + eg->idnum = idnum;
>> + eg->metric_name = pe->metric_name;
>> + eg->metric_expr = pe->metric_expr;
>> + eg->metric_unit = pe->unit;
>> + list_add_tail(&eg->nd, group_list);
>> + ret = 0;
>> +
>> + return ret;
>> +}
>> +
>> static int metricgroup__add_metric(const char *metric, struct strbuf *events,
>> struct list_head *group_list)
>> {
>> @@ -493,35 +585,17 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
>> continue;
>> if (match_metric(pe->metric_group, metric) ||
>> match_metric(pe->metric_name, metric)) {
>> - const char **ids;
>> - int idnum;
>> - struct egroup *eg;
>>
>> pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);
>>
>> - if (expr__find_other(pe->metric_expr,
>> - NULL, &ids, &idnum) < 0)
>> - continue;
>> - if (events->len > 0)
>> - strbuf_addf(events, ",");
>> -
>> - if (metricgroup__has_constraint(pe))
>> - metricgroup__add_metric_non_group(events, ids, idnum);
>> + if (strstr(pe->metric_expr, "?"))
>> + ret = metricgroup__add_metric_runtime_param(events,
>> + group_list, pe);
>> else
>> - metricgroup__add_metric_weak_group(events, ids, idnum);
>> -
>> - eg = malloc(sizeof(struct egroup));
>
> *eg
>> - if (!eg) {
>> - ret = -ENOMEM;
>> - break;
>> - }
>> - eg->ids = ids;
>> - eg->idnum = idnum;
>> - eg->metric_name = pe->metric_name;
>> - eg->metric_expr = pe->metric_expr;
>> - eg->metric_unit = pe->unit;
>> - list_add_tail(&eg->nd, group_list);
>> - ret = 0;
>> + ret = metricgroup__add_metric_param(events,
>> + group_list, pe);
>> + if (ret == -EINVAL)
>> + continue;
>> }
>> }
>> return ret;
>> diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
>> index 475c7f912864..81224ba1270d 100644
>> --- a/tools/perf/util/metricgroup.h
>> +++ b/tools/perf/util/metricgroup.h
>> @@ -34,4 +34,5 @@ int metricgroup__parse_groups(const struct option *opt,
>> void metricgroup__print(bool metrics, bool groups, char *filter,
>> bool raw, bool details);
>> bool metricgroup__has_metric(const char *metric);
>> +int arch_get_runtimeparam(void);
>> #endif
>> diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
>> index 0fd713d3674f..92c4c9abbaa0 100644
>> --- a/tools/perf/util/stat-shadow.c
>> +++ b/tools/perf/util/stat-shadow.c
>> @@ -777,6 +777,14 @@ static void generic_metric(struct perf_stat_config *config,
>> }
>>
>> if (!metric_events[i]) {
>> +
>> + if (strstr(metric_expr, "?")) {
>> + char *tmp = strrchr(metric_name, '_');
>> +
>
> So at this point a metric name is guaranteed to have a _?

Yes, because we are appending '_' with parameter value in metric name
when we adding these events in 'group_list'. So, I added it, because
we can have multiple values of that runtime_parameter, so by appending it
in metric name, we can understand to which event the counter data belongs.
Thanks for reviewing the patch, I will send updated patch.

Thanks,
Kajol
>
>> + tmp++;
>> + expr__runtimeparam = strtol(tmp, &tmp, 10);
>> + }
>> +
>> if (expr__parse(&ratio, &pctx, metric_expr) == 0) {
>> char *unit;
>> char metric_bf[64];
>> --
>> 2.18.1
>>
>